Abstract/Summary

The subtribe Hyacinthinae Parl. consists of more than 290 species of mostly spring-flowering bulbs, distributed across the Mediterranean, Irano-Turanian floristic region, and the Far East, and several of which have importance in horticulture. Morphological work in the 1990’s, proposed that Hyacinthinae consists of 21 genera. However, these generic boundaries have not been extensively tested using phylogenomics, leaving the taxonomy and evolution of the group relatively unexplored. In this thesis, I aimed to gain a better understanding about the evolution and taxonomy of the diverse subtribe Hyacinthinae by comprehensively sampling across its taxonomic and geographic range and constructing both nuclear and plastome phylogenies. These phylogenies were used to test the morphologically defined generic boundaries of Hyacinthinae, revealing that morphology and DNA were largely congruent. However, inclusion of more taxa showed that some generic boundaries do need redefining, specifically within the Fessia clade. While morphology and DNA are broadly congruent within the wider Hyacinthinae, a detailed phylogenomic examination of the horticulturally important genus Muscari s.lat., showed high levels of incongruence between the morphologically distinct subgenera Muscari and Leopoldia, likely a result of incomplete lineage sorting. Finally, historical biogeographical analyses, based upon plastid protein coding genes, suggest a Late Oligocene origin of the subtribe. Distribution of the three clades and Barnardia are heavily influenced by vicariance events throughout the Late Oligocene and Early Miocene. Meanwhile, early divergence within the three main clades, coincided with the Mid-Miocene Climatic Optimum, challenging the common assumption that plant diversity in the Mediterranean is primarily influenced by the onset of Mediterranean climate. Overall, this thesis has provided a crucial phylogenetic and taxonomic framework for Hyacinthinae. However, while it has answered many questions regarding the subtribe’s taxonomy, distribution, and diversity, it has also highlighted several areas which require further investigation.